Technical Field
The present invention relates to a powder collection container that collects waste powder such as waste toner and waste developer, and also to an image forming apparatus including such a powder collection container.
Background Art
In a developing device that uses two component developer, toner is sequentially consumed by a development operation whereas carrier remains in the developing device without being consumed. Accordingly, as the carrier is more frequently stirred in the developing device, the charging performance of the developer is gradually deteriorated. The developing device, therefore, employs a trickle system, discharges developer that has become excessive while supplying the carrier in a trickle, and discards and collects such excess developer in a collection container as deteriorated developer. Successive repetition of such supply and discharge causes the deteriorated developer in the developing device to be replaced with newly supplied toner and carrier, which makes it possible to maintain the charging performance of the toner and to prevent deterioration in copy image quality. In addition, an image forming apparatus cleans residual toner on the surface of a photoreceptor, and residual toner of a secondary transfer portion, and then collects the residual toner in a collection container. The collection container for the deteriorated developer and the residual toner is installed just on the inner side of an opening/closing door on the rear side of the image forming apparatus. The deteriorated developer and the residual toner are carried out to the collection container through a discharge path.
On the one hand, such an image forming apparatus that employs the trickle system is a machine with a high speed specification and has a configuration in which the deteriorated developer and the residual toner are merged together and then are collected in a single collection container through the discharge path. On the other hand, a small image forming apparatus with a middle and low speed specification, for example, has a problem that the rear side area is not large enough to provide a space in which a path for merging developer and toner is arranged.
Japanese Patent Laid-Open publication No. 2010-72310 discloses that an image forming apparatus of a tandem type includes a collection container capable of collecting color residual toner and black deteriorated developer in separate collection chambers in a single collection container through separate discharge paths and of individually discarding the color residual toner and the black deteriorated developer through separate waste holes.